feat: 36_valid_sudoku

36_valid_sudoku/main.cpp

@@ -0,0 +1,60 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+class Solution {
+   public:
+    bool checkRepeat(bitset<9>& bs, char c) {
+        if (c != '.') {
+            int d = c - '1';
+            if (bs[d]) return true;
+            bs.flip(d);
+        }
+        return false;
+    }
+
+    bool isRowValid(vector<vector<char>>& board, int row) {
+        bitset<9> bs(0);
+        for (auto c : board[row]) {
+            if (checkRepeat(bs, c)) return false;
+        }
+        return true;
+    }
+
+    bool isColValid(vector<vector<char>>& board, int col) {
+        bitset<9> bs(0);
+        for (int i = 0; i < 9; i++) {
+            char c = board[i][col];
+            if (checkRepeat(bs, c)) return false;
+        }
+        return true;
+    }
+
+    bool isSecValid(vector<vector<char>>& board, int row, int col) {
+        bitset<9> bs(0);
+        for (int i = row; i < row + 3; i++) {
+            for (int j = col; j < col + 3; j++) {
+                char c = board[i][j];
+                if (checkRepeat(bs, c)) return false;
+            }
+        }
+        return true;
+    }
+
+    bool isValidSudoku(vector<vector<char>>& board) {
+        for (int i = 0; i < 9; i++) {
+            if (!isRowValid(board, i)) return false;
+        }
+
+        for (int i = 0; i < 9; i++) {
+            if (!isColValid(board, i)) return false;
+        }
+
+        for (int i = 0; i < 9; i += 3) {
+            for (int j = 0; j < 9; j += 3) {
+                if (!isSecValid(board, i, j)) return false;
+            }
+        }
+
+        return true;
+    }
+};